Crystals and structural features of AtNRP2. (a) Crystals obtained for AtNRP2 NT/CT in AmSO4 Suite (Qiagen) and tested for diffraction (Conditions (i) 3, (ii) 25, (iii) 27, (iv) 32, (v) 40, (vi) 91). All the crystals were tested for diffraction limits. The best diffraction data was obtained for the big crystal from condition 27, and the collected data was used for structure work. (b) The crystal structure of AtNRP2, showing the pseudo-symmetric two-fold axis. (c) The distribution of hydrophobic residues along the long dimerization helix of AtNRP2. (d) The structure of AtNRP2 monomer, showing the domain organization, where domain I consist of a long dimerization helix (α1) and domain II includes both α-helices and β-strands.